1. Field of the Invention
The present invention relates to an electronic device having multiple power supply systems.
2. Description of the Related Art
Conventionally, there are electronic devices that operate using power (power source) from a power supply unit such as an AC power source. Such electronic devices have a power source connector to which a power supply plug is connected. The power supply plug is provided on a cable for connecting the power supply apparatus to the electronic device.
Among such conventional electronic devices equipped with a power source connector is an electronic device that operates using power supplied from an external apparatus, such as host computer. The power is supplied through an interface for exchanging data with the external apparatus and the interface is implemented by, for example, a versatile USB, an IEEE1394 compliant connector, and the like.
Electronic devices that operate using power supplied from an external apparatus are equipped with a power source connector as a standard and may be optionally equipped with an interface connector having a power supply terminal. In addition to a power source connector, such electronic devices are equipped with an interface connector having a power supply terminal.
For example, according to a technique disclosed in Japanese Utility Model Publication No. H03-15319, a first interface is disposed on a motherboard, while a second interface for a data reception scheme different from that of the motherboard is disposed on a sub-board together with a member covering the terminal of the first interface connector. The first interface connector electrically connects the sub-board to the motherboard.
Further, according to a technique, for example, disclosed in Japanese Patent Application Laid-Open Publication No. 2009-224088, openings are disposed at various aspects of the casing of an electronic device. Terminals are disposed opposing each of the openings, among which, one opening is opened while the other openings are blocked by a blocking unit.
Since the conventional arts above dispose, in addition to a power source connector, an interface connector having a power supply terminal and continuously maintain a state in which the power supply plug can be connected to the power source connector, a situation occurs where the power supply plug is connected to the power source connector in a state where a plug is connected to the interface connector having the power supply terminal.
In this state, for example, if the power supplied through the power connector is greater than that supplied from the interface connector having the power supply terminal, the excess power flows back to the external apparatus connected via the interface connector and data stored in the external apparatus, apparatuses connected to the external apparatus or the apparatus itself is may be damaged.
Since the technique recited in Japanese Utility Model Publication No. H03-15319 separately disposes on the sub-board, a member covering the terminal of the first interface, a problem arises in that the number of components increases. Further, since the blocking units of the technique recited in Japanese Patent Application Laid-Open Publication No. 2009-224088 are independent components, the problem of increased components arises and because the blocking units are moveable, space for the blocking units to move has to be established, increasing the size of the electronic device.